The relationship between heart size and electrical function is not fully understood.
Existing electrophysiological theories do not adequately explain the observed non-linear scaling of the PR interval with heart size.
Purpose:
To investigate the non-linear relationship between heart size and atrioventricular (AV) transmission time.
To explore alternative explanations for AV nodal delay beyond traditional conduction properties.
Summary:
Heart size scales dramatically with body weight, yet the PR interval (a measure of AV transmission time) shows a much smaller increase, forming an S-shaped curve.
The AV node's contribution to AV delay likely decreases with larger heart sizes, challenging current models.
Viewing the AV node as a pacemaker modulated by atrial activity, rather than a simple conduction cable, may explain its behavior.
Impact:
This research offers a new perspective on AV nodal function and its modulation during atrial fibrillation.
Findings may influence therapeutic strategies for patients with atrial fibrillation and related conduction abnormalities.